288,027 research outputs found
Impending anterior ischemic optic neuropathy with elements of retinal vein occlusion in a patient on interferon for polycythemia vera.
We describe the course and likely pathophysiology of impending anterior ischemic optic neuropathy (AION) and retinal vein occlusion in a 56-year-old man with polycythemia vera managed with interferon alpha for 2 years. Our patient presented with decreased vision, scintillating scotomata, and floaters. Fundus examination findings and results of a fluorescein angiogram led to the diagnosis of impending AION and retinal vein occlusion. Considering that both polycythemia vera and interferon have possible influences on vascular occlusion and optic disc edema, we stopped interferon treatment and immediately attempted to treat the polycythemia vera empirically with pentoxifylline and any interferon-associated inflammation with prednisone. Our patient experienced complete resolution of fundus abnormalities and return of normal vision within 3 weeks, which may be attributed to our successful treatment of both etiologies. Thus, further study is warranted to elucidate the treatment of both polycythemia vera and interferon-induced impending AION
Viral infections in interferon-gamma receptor deficiency.
Interferon-gamma receptor deficiency is a recently described immunodeficiency that is associated with onset of severe mycobacterial infections in childhood. We describe the occurrence of symptomatic and often severe viral infections in 4 patients with interferon-gamma receptor deficiency and mycobacterial disease. The viral pathogens included herpes viruses, parainfluenza virus type 3, and respiratory syncytial virus. We conclude that patients with interferon-gamma receptor deficiency and mycobacterial disease have increased susceptibility to some viral pathogens
Inhibition of type I interferon induction and signalling by mosquito-borne flaviviruses
The Flavivirus genus (Flaviviridae family) contains a number of important human pathogens, including dengue and Zika viruses, which have the potential to cause severe disease. In order to efficiently establish a productive infection in mammalian cells, flaviviruses have developed key strategies to counteract host immune defences, including the type I interferon response. They employ different mechanisms to control interferon signal transduction and effector pathways, and key research generated over the past couple of decades has uncovered new insights into their abilities to actively decrease interferon antiviral activity. Given the lack of antivirals or prophylactic treatments for many flaviviral infections, it is important to fully understand how these viruses affect cellular processes to influence pathogenesis and disease outcome. This review will discuss the strategies mosquito-borne flaviviruses have evolved to antagonise type I interferon mediated immune responses
Atorvastatin combined to interferon to verify the efficacy (ACTIVE) in relapsing-remitting active multiple sclerosis patients: a longitudinal controlled trial of combination therapy.
A large body of evidence suggests that, besides their cholesterol-lowering effect, statins exert anti-inflammatory action. Consequently, statins may have therapeutic potential in immune-mediated disorders such as multiple sclerosis. Our objectives were to determine safety, tolerability and efficacy of low-dose atorvastatin plus high-dose interferon beta-1a in multiple sclerosis patients responding poorly to interferon beta-1a alone. Relapsing–remitting multiple sclerosis patients, aged 18–50 years, with contrast-enhanced lesions or relapses while on therapy with interferon beta-1a 44 mg (three times weekly) for 12 months, were randomized to combination therapy (interferon+atorvastatin 20mg per day; group A) or interferon alone (group B) for 24 months. Patients underwent blood analysis and clinical assessment with the Expanded Disability Status Scale every 3 months, and brain gadolinium-enhanced magnetic resonance imaging at screening, and 12 and 24 months thereafter. Primary outcome measure was contrast-enhanced lesion number. Secondary outcome measures were number of relapses, EDSS variation and safety laboratory data. Forty-five patients were randomized to group A (n 1⁄4 21) or B (n 1⁄4 24). At 24 months, group A had significantly fewer contrast-enhanced lesions versus baseline (p 1⁄4 0.007) and significantly fewer relapses versus the two pre-randomization years (p < 0.001). At survival analysis, the risk for a 1-point EDSS increase was slightly higher in group B than in group A (p 1⁄4 0.053). Low-dose atorvastatin may be beneficial, as add-on therapy, in poor responders to high-dose interferon beta-1a alone
An unbiased genetic screen reveals the polygenic nature of the influenza virus anti-interferon response.
Influenza A viruses counteract the cellular innate immune response at several steps, including blocking RIG I-dependent activation of interferon (IFN) transcription, interferon (IFN)-dependent upregulation of IFN-stimulated genes (ISGs), and the activity of various ISG products; the multifunctional NS1 protein is responsible for most of these activities. To determine the importance of other viral genes in the interplay between the virus and the host IFN response, we characterized populations and selected mutants of wild-type viruses selected by passage through non-IFN-responsive cells. We reasoned that, by allowing replication to occur in the absence of the selection pressure exerted by IFN, the virus could mutate at positions that would normally be restricted and could thus find new optimal sequence solutions. Deep sequencing of selected virus populations and individual virus mutants indicated that nonsynonymous mutations occurred at many phylogenetically conserved positions in nearly all virus genes. Most individual mutants selected for further characterization induced IFN and ISGs and were unable to counteract the effects of exogenous IFN, yet only one contained a mutation in NS1. The relevance of these mutations for the virus phenotype was verified by reverse genetics. Of note, several virus mutants expressing intact NS1 proteins exhibited alterations in the M1/M2 proteins and accumulated large amounts of deleted genomic RNAs but nonetheless replicated to high titers. This suggests that the overproduction of IFN inducers by these viruses can override NS1-mediated IFN modulation. Altogether, the results suggest that influenza viruses replicating in IFN-competent cells have tuned their complete genomes to evade the cellular innate immune system and that serial replication in non-IFN-responsive cells allows the virus to relax from these constraints and find a new genome consensus within its sequence space.
IMPORTANCE In natural virus infections, the production of interferons leads to an antiviral state in cells that effectively limits virus replication. The interferon response places considerable selection pressure on viruses, and they have evolved a variety of ways to evade it. Although the influenza virus NS1 protein is a powerful interferon antagonist, the contributions of other viral genes to interferon evasion have not been well characterized. Here, we examined the effects of alleviating the selection pressure exerted by interferon by serially passaging influenza viruses in cells unable to respond to interferon. Viruses that grew to high titers had mutations at many normally conserved positions in nearly all genes and were not restricted to the NS1 gene. Our results demonstrate that influenza viruses have fine-tuned their entire genomes to evade the interferon response, and by removing interferon-mediated constraints, viruses can mutate at genome positions normally restricted by the interferon response
Raised serum transaminases during treatment with pegylated interferon for chronic hepatiti C
Introduction : Serum transaminases rose significantly in 7 patients with chronic hepatitis C, genotypes 2 and 3, who were treated with pegylated interferon and ribavirin.
Methods : 219 patients with chronic hepatitis C, genotypes 2 and 3, were treated between 2005 and 2011 following the same protocol. For the 7 patients presented in this paper, the initial liver screen revealed chronic hepatitis C infection only. The same liver screen was repeated following the transaminase rise during the treatment period and failed to reveal additional comorbidity.
Results : 5 male and 2 female patients with chronic hepatitis C experienced a rise in serum transaminases after commencement on treatment with pegylated interferon and ribavirin. They all achieved rapid and end of treatment virological responses. 3 of the patients achieved sustained virological response and 4 relapsed. There was no evidence to suggest that steatosis, development of autoimmunity or intercurrent illness was the cause of the liver injury. In 3 out of 7 patients, the level of transaminases exhibited a downward trend after pegylated interferon was changed to non pegylated interferon. Additionally, it is evident that in those patients whose treatment was temporarily or permanently aborted, the rise in transaminases rapidly improved and returned to baseline.
Conclusion : Our experience suggests the possibility of a toxic reaction to polyethylene glycol in a small number of patients being treated with pegylated interferon, resulting in an acute hepatitic response which resolved when therapy was stopped or switched to non-pegylated interferon
Alpha/beta and gamma interferons are induced by infection with noncytopathic bovine viral diarrhea virus in vivo
In contrast to the results of previous in vitro studies, experimental infection of calves with noncytopathic bovine viral diarrhea virus (ncpBVDV) was found to induce strong alpha/beta and gamma interferon responses in gnotobiotic animals. These responses were associated with depressed levels of transforming growth factor β (TGF-β) in serum. The results of this study indicate that the immunosuppression caused by ncpBVDV is not associated with low interferon responses or elevated levels of TGF-β
Interleukin -2 ( Il-2 ) and Gamma Interferon ( Ifn ? ) of Lymphocyte Culture Supernatant in Iron Deficiency Anemia Patients with Infection
Iron is an essential nutrient for every living cells because of it role as molecule fortransport of oxygen, as well as DNA synthesis through synthesis of ribonucleotidereductase. Iron deficiency anemia patients, especially pregnant women and children aremore susceptible to infection because of deterioration of their immune response. This wassupported by findings of decreased in phagocytic activities of white blood cells and Tcelllymphocyte proliferation impairment. Iron deficiency anemia (IDA) patients alsoaffect working capacities hence diminishing working outcomes. Although the underlyingmechanism of immune defect in iron deficiency anemia is not clearly understood,multifactor events considered play their contributing roles such as abnormality ofribonucleotide reductase enzym, impairment of T-cell proliferation and activities, alteredcytokine production of IL-2 and IFN?.The study was done to asses the relationship of IL-2 and gamma IFN withinfection in IDA patients on lymphocyte culture supernatant of IDA patients. Study wasconducted on cross-sectional analytic design. Sixty-four iron deficiency anemia patientstreated in Sanglah General Teaching Hospital were recruited, and 31 (48.4%) out of 64IDA patients were man and 33 (51.6%) women, have been selected for the study. Thisstudy found 17 (26.7%) IDA patients with infection, aged 38 ± 14.48 years and 47(73.3%) IDA patients without infection, with age average of 40.5 ± 14.4 years. Allvariables of data characteristics examined did not indicate any statistical significantdifference between group of IDA patients with infection and those without infection. Theaverage level of hemoglobin between the two groups did not differ statistically. Similarresult was obtained if samples were differentiated into severe (Hb< 7g/dl) and mildanemia. The study also revealed that there were no differences of cytokine level observedbetween older and younger age (upper and below 44.5 years) in IDA patients withinfection and without infection. Furthermore, no differences of cytokine level were foundbased on gender between IDA male 10.9 (8.60 – 12,65) (pg/l) patients and IDA femalepatients 10.6 (7.50 – 13.43) (pg/l) with Z -0.490, p =0.624. Nevertheless, significantdifferences were noted between supernatant of IL-2 and IFN? in IDA patients withinfection when compared to IDA patients without infection (Z= - 2.509, p= 0.012 forsupernatant IL-2; and Z= -2.569, p= 0.010 for supernatant IFN?).The study conclusion is that level of IL-2 and IFN? from lymphocyte culturesupernatant of patient suffered from IDA with infection is significantly lower whencompared to IDA patient without infection. It therefore summarized that lower level ofIL-2 and gamma IFN in patients suffered from iron deficiency impaired their immune response to certain infections therefore this findings support the theory that IDA patientsmore susceptible to get infected
Regulation of Murine Class I Genes by Interferons is Controlled by Regions Located Both 5' and 3' to the Transcription Initiation Site
Interferons regulate the expression of a large number of mammalian genes, including the major histocompatibility antigen genes. To investigate the mechanisms involved in interferon action, we have analyzed the ability of murine H-2Ld and H-2Dd DNA sequences to control the responses to interferon. The results indicate that interferon regulation of class I gene expression is complex and involves at least two mechanisms that are dependent on class I sequences located upstream and downstream to the transcription initiation site. In transfected mouse L cells, both of these regions are required for full enhancement of class I gene expression, with the major portion of the response controlled by the sequences located 3' to the transcription initiation site. The fine-mapping analysis of the 5' region-encoded response also suggests that recombinant alpha and gamma interferons may exert their effects on class I gene expression by using different cis-acting regulatory sequences
- …